The present invention relates to a microphone mounting structure, and in particular, a microphone mounting structure which permits easy and reliable conversion of a conventional respirator and/or bubble suit to a sound amplifying respirator and/or bubble suit.
It is known that conventional respirators and/or bubble suits make communications difficult between persons wearing the respirators and/or bubble suits. In particular, the wearer""s voice is muffled and difficult to detect over significant distances. This problem is exacerbated when there is background noise, as during firefighting and other similarly hazardous emergency operations. In response to this problem, several attempts have been made to provide sound amplifying respirators and/or masks which facilitate communications among the wearers of the respirators and masks. Examples of such respirators and masks are illustrated by the following U.S. Patents:
Although the above exemplary respirators and masks are generally effective, there are several disadvantages associated therewith. The Joscelyn patent, for example, teaches a mounting structure for the microphone which is integrally formed with the mask. Thus, retro-fitting of existing masks with the arrangement of Joscelyn would be very difficult and time-consuming.
Still other disadvantages are associated with one or several ones of the above exemplary respirators and masks. These disadvantages include significant reductions in amplification quality resulting in distortion of the amplified voice; the need for expensive and excessively complex circuitry or manufacturing techniques; serious distortion if the mask is frequently bumped or otherwise subject to frequent quick movements; incompatibility with some irregularly shaped masks and smaller masks, such as filter masks; mounting of the microphone assembly to the mask using a threaded connection which may become loosened during extended use, such loosening of the threaded connection possibly compromising the air-tightness of the mask and thereby posing an extreme danger to the user of the masks in hazardous environments; and difficulty in removing the microphone temporarily from the mask for purposes of cleaning the mask.
It is a primary object of the present invention to overcome the deficiencies of the prior art by providing a microphone mounting structure which permits easy and reliable conversion of a conventional respirator and/or bubble suit into a sound amplifying respirator and/or bubble suit.
Another object of the present invention is to provide a small, light-weight microphone mounting structure which is compatible with almost any respirator mask, including paper filter masks, and positively locks thereto to prevent inadvertent loosening of the mounting structure or leakage through the mask.
Yet another object of the present invention is to provide a microphone mounting structure which does not require a pre-existing mounting feature or connector on the respirator mask or bubble suit, and instead breaches the mask or bubble suit and then re-establishes the air-tight characteristics thereof.
Still another object of the present invention is to provide a microphone mounting structure which does not require complex or expensive circuitry, nor does it require complex signal transmission means such as infra-red transmitters and receivers.
A further object of the present invention is to provide a microphone mounting structure which provides direct electrical connections between a microphone inside a respirator mask and/or bubble suit, and amplifying circuitry so as to provide enhanced voice signal quality.
Another object of the present invention is to provide a microphone mounting structure with an amplification circuit that provides maximum voice signal quality for voices detected within the mask and/or bubble suit by the microphone.
To achieve these and other objects, the present invention comprises a microphone mounting structure for mounting a microphone to a respiratory mask and/or bubble suit through a hole therein. The microphone mounting structure is thus able to convert virtually any conventional respiratory mask or bubble suit into a sound amplifying respiratory mask or bubble suit.
The microphone mounting structure comprises a tubular plug, a sleeve, and a tubular locking mechanism. The tubular plug has a closed end, an open end and a central portion disposed therebetween. The closed end of the tubular plug has a larger outer diameter than the outer diameter of the central portion. The open end has a plurality of resilient fingers defined by slots in the open end, the resilient fingers having Finger tips which project radially out with respect to the tubular plug. The tubular plug further comprises electrical contact means for electrically connecting an interior of the tubular plug with an exterior of the tubular plug.
The sleeve receives the microphone and has an outer diameter substantially equal to the inner diameter of the tubular plug so that the sleeve fits coaxially inside the tubular plug. Preferably, the sleeve has an internal diameter which matches the outer diameter of the microphone so that the microphone is frictionally retained within the sleeve. The sleeve, however, is preferably longer than the central portion and open end of the tubular plug. In this way, a portion of the sleeve projects out from the tubular plug and this, in turn, facilitates removal of the sleeve from within the tubular plug using, for example, needle-nosed pliers.
A microphone cover may also be provided which fits snugly over the projecting sleeve portion and protects the microphone from moisture, dust, and the like. The microphone cover is preferably arranged only over the projecting sleeve portion so that the resilient fingers of the tubular plug remain exposed for easy inspection.
The tubular locking mechanism cooperates with the tubular plug to lock the microphone mounting structure to the respiratory mask. In particular, the tubular locking mechanism includes an inner diameter substantially equal to the outer diameter of the central portion and a longitudinal length only slightly shorter than the combination of the central portion and the open end. By providing these dimensions, the tubular locking mechanism is slidable over the resilient fingers after the tubular plug has been inserted through the hole in the respiratory mask. Doing so, in turn, forces the resilient fingers radially inwardly until the entire tubular locking mechanism has passed over the finger tips of the resilient fingers, at which time the finger tips snap radially outwardly to thereby lock the microphone mounting structure to the respiratory mask. The respiratory Task, consequently, remains sandwiched and locked between the front end of the tubular locking mechanism and the closed end of the tubular plug.
The microphone mounting structure of the present invention preferably comprises three electrical contacts extending radially through the sleeve and arranged for electrical connection to the electrical contact means in the tubular plug. In addition, three electrical wires are provided for electrically connecting the electrical contacts to the microphone.
The microphone mounting structure preferably also comprises an internal alignment slot extending longitudinally along the central portion and open end of the tubular plug, and an external alignment tab which projects radially out from the sleeve for alignment with the internal alignment slot of the tubular plug. The alignment slot and tab are arranged such that, whenever the external alignment tab is received in the internal alignment slot, the external alignment tab prevents axial rotation of the sleeve with respect to the tubular plug. This arrangement helps keep the three electrical contacts of the sleeve aligned with the electrical contact means of the tubular plug.
Preferably, a socket is also provided at the closed end of the tubular plug. The socket receives an electrical plug which electrically connects the electrical contact means to an amplification circuit.
The microphone mounting structure can further comprise a circumferential flange projecting radially outwardly from the front end of the tubular locking mechanism. At least one resilient washer is preferably disposed coaxially around the central portion of the tubular plug, between the front end of the tubular locking mechanism and the closed end of the tubular plug.
According to a preferred arrangement, at least one and preferably all of the finger tips project radially outwardly and backwardly toward the central portion so that each of the corresponding resilient fingers has a semi-arrow-shaped distal end. In addition, the tubular locking mechanism includes an externally bevelled back end for lockingly engaging the semi-arrow-shaped distal end of the resilient fingers.
Amplification circuitry provides output sounds representative of the oral sounds which the microphone detects within the mask. The amplification circuitry may be provided entirely in a separate housing, or alternatively, may be manufactured using integrated chip technology so that certain circuit components are miniaturized and built into the closed end of the tubular plug. According to the latter arrangement, a speaker and power supply portions of the amplification circuitry would remain in a separate housing.
For purposes of this disclosure, the term xe2x80x9crespiratory maskxe2x80x9d is intended to broadly encompass all types of respiratory masks, including those attached to a supply of gas and those which merely filter air, including conventional paper filter masks.
An alternative embodiment of the mounting structure requires no sleeve and instead utilizes a microphone having socket sleeves. The socket sleeves are arranged so as to receive electrically conductive pins of the tubular plug and thereby establish electrical communication between the microphone and electrical contacts within the tubular plug. In the alternative embodiment, a grommet may surround the microphone; however, the grommet preferably includes no conductive elements.
The mounting structure of the present invention may be combined with other similar mounting structures disposed through respective holes in a bubble suit (or other protective barrier) to facilitate not only verbal communication through the respiratory mask, but also verbal communication through the bubble suit.
In addition, earphones inside a bubble suit may be electrically connected, via a mounting structure of the present invention, to an external communication device outside the bubble suit. When the external communication device includes a microphone, sounds and conversations which occur outside the bubble suit may be easily detected inside the bubble suit. Similarly, when the external communication device includes a transceiver, bi-directional communication is facilitated between the wearer of the bubble suit and remotely located personnel having similar transceivers.
In another embodiment of the invention, a cylinder is configured as a special sleeve for use with the plug of the alternative embodiment having electrically conductive pins. The cylinder has the same general size and shape as the sleeve, and is essentially used in the same manner. However, the cylinder is capable of receiving either a microphone or an electric plug, whereas the sleeve only receives a microphone.
The above and other objects and advantages will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.